According to the current scientific literature, the therapeutic action of stem cells may be due to two mechanisms: differentiation of stem cells into resident cells and release of regenerative trophic factors by stem cells. The respective contributions of these two mechanisms remain to be clarified, although it has been suggested that stem cells do not develop into mature cells of the injured tissue, but they rather convey vital factors to this tissue, which can then return to proliferate and differentiate, regenerating itself (A I Caplan and J E Denni, Mesenchymal Stem Cells as Trophic Mediators. Bioch J. Cell 98:1076-1084, 2006).
Stem cell therapy has many problems related not only to the costs and technical and practical complications but also ethical and religious scruples.
Stem cell therapy is feasible only by injection or, in some cases, topically, and not orally The supernatant of cultured stem cells contains growth factors, cytokines, chemotactic factors etc., which are believed to be responsible for the beneficial effect of stem cell therapy on tissue growth and/or repair.
The use of the vital factors isolable from the supernatant of stem cells has, however, not only the same ethical problems of the use of the stem cells themselves but also very high costs.
It is known that some mammalian tissues and biological fluids, namely serum, placenta and colostrum, contain cytokines, growth factors, chemotactic factors, and other components usually found also in the supernatant of stem cell cultures.
Several therapeutic applications have been disclosed in the past for pure colostrum or of extracts or fractions thereof as well as for placenta extracts. For instance, a review of clinical uses of colostrum is reported in Alternative Medicine Review 8(4), 2003, page 378 and in Int. J. Clin. Pharmacol and Therap., 46(5), 2008, 211-225 and in International Dairy Journal, 16, 2006, 1415-1420.
Therapeutic uses of colostrum or fractions thereof are also reported in EP 743060, WO 98/51316, WO 94/16675, WO 98/36759, WO 95/00155, WO 2007/000648, FR 2487676, WO 98/14473, WO 99/64022, WO 2008/103023 and in WO 2006/029494. The latter discloses the extraction of growth and differentiating factors from colostrum but the process disclosed necessarily involves the loss of important components (e.g. cytokines, stem cell stimulating factors, chemiotactic factors and antibacterial/antiviral factors) of pure colostrum. None of the prior art documents discloses compositions derived from easily available mammalian sources containing most of if not all components of stem cell cultures supernatant, as a substitute for stem cell therapy.